Composite catheter stabilizing devices, methods of making the same and catheter extracting device

ABSTRACT

A composite catheter stabilizing device, a catheter assembly including such a stabilizing device and a device for removing a catheter assembly are provided. The stabilizing device includes a cuff having a first and second edge which is configured to be positioned around a catheter. The device further includes a first and second end piece. The first and second end pieces have internal surfaces defining tubular openings which extend through the end pieces. The first and second end pieces are tapered from first sides which abut the edges of the cuff to second sides and the second sides of the end pieces are configured for receiving a catheter in facing engagement. The device for removing a catheter assembly includes a handle and a head having an external gripping surface which is sized for inserting into a lumen of a catheter assembly having a tissue ingrowth cuff for gripping an internal surface of the catheter assembly within the cuff and dislodging the cuff from surrounding tissue.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of application Ser. No. 08/611,927,filed Mar. 6, 1996, now U.S. Pat. No. 5,830,184, entitled CompositeCatheter Stabilizing Devices, Methods of Making the Same and CatheterExtracting Device. The entire disclosure of application Ser. No.08/611,927 as filed is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a new catheter assembly, a catheterstabilizing device and a device for removing a catheter assembly havinga catheter stabilizing device.

BACKGROUND OF THE INVENTION

Catheters, shunts, drainage tubes and the like, generally referred toherein as catheters, may be located in various locations within thehuman body for the introduction and removal of fluid from the body. Oncein place, such catheters are typically anchored by a stabilizing deviceor sutured in place. Stabilizing devices generally are provided inseveral different types. Many catheters include a winged collar or cuffhaving suture holes formed in an outer area of the device. The collar orcuff freely rotates about the catheter. Catheters may also be taped to apatient's skin, however, taping alone is generally not sufficientlyreliable to stabilize the device.

Another common catheter stabilizing device is a tissue-ingrowth cuff.Such a cuff is typically made of Dacron® or a similar biocompatiblematerial, and is attached by an adhesive layer to the outer surface of acatheter cannula. The cuff is generally located on the catheter suchthat when a distal portion of the catheter is in position in a locationto be catheterized, the cuff is positioned external to the catheterizedpart of the body, but below the surface of the skin in subcutaneoustissue.

In some cases, the cuff is positioned on the catheter such that when thedistal portion of the catheter is inserted in the body part, the cuff islocated in a subcutaneous tunnel. The tunnel is formed by a tunnellingtool, such as a trocar, either before or after cannulation of the vesselwith the distal portion of the catheter. The proximal portion of thecatheter having the cuff is drawn through the tunnel by the tool whilethe tool passes through the subcutaneous tissue. The cuff is generallysized such that when the procedure is done, the cuff will fit snugly inthe tunnel or other area.

After a period of time, the surrounding tissue grows into the fabric ofthe cuff such that the catheter is stabilized in the catheterizedlocation. In addition, the catheterized location and the subcutaneoustunnel are sealed off, preventing foreign bodies from entering the woundand blood from exiting or pooling around the catheter near the exitsite, thereby preventing patient infection. While such fabric cuffs areinexpensive to make and are generally effective at stabilizing acatheter, they are also difficult to remove.

In order to remove such a cuff from ingrown subcutaneous tissue, such asa tunnel, a physician has to detach the cuff by cutting around the cuffwith a scalpel. The physician has to cut the subcutaneous tissuesurrounding all edges of the cuff into which tissue has grown. Tissuegrowth occurs substantially transverse to the longitudinal axis of thecuff around the outer circumference of the cuff. In addition, tissuegrowth occurs at angles oblique to the longitudinal axis of the cuffalong both of the cuff's side edges. The physician must cut around thecircumference of the cuff and both side edges to detach the cuff in adifficult, time-consuming surgical procedure that can increase patientbleeding. Such prolonged surgery and increased bleeding presents severalrisks to both the physician and patient, including the increased risk ofinfection. The procedure may also possibly contribute to an increasedchance of scar tissue build-up within the subcutaneous area such thatpatients requiring multiple catheterization procedures may becomeincreasingly difficult to catheterize.

The fabric cuffs also pose problems in the subcutaneous tunnellingprocedures. Because the cuffs are sized to provide a snug fit in thesubcutaneous area, they are difficult to pull smoothly through thetunnel. With catheters formed of softer durometer materials, such aspellethane and silicone, for example, the cuffs increase the risk thatthe catheter will snap or break apart during the tunnelling or removalprocedure, and tend to elongate the tube and alter its dimensions. Thestress placed on the proximal end of the catheter during the tunnellingprocedure or during removal to pull the catheter through the tunnel isconcentrated at the location of the cuff. As the cuff fits snugly withinthe subcutaneous tunnel, frictional forces against the tunnel wallaffect the tunnelling and removal of the catheter. If the catheterbreaks during removal, the physician may have to perform a furtherprocedure to remove the broken-off distal portion of the catheter leftwithin the patient. If the catheter breaks during the initial tunnellingprocedure, the physician may have to completely recatheterize thepatient.

Based on the foregoing disadvantages of prior art catheter stabilizingdevices, particularly fabric cuffs, there is a need in the art for astabilizing device which prevents the pooling of blood and invasion offoreign bodies by sealing a catheterized location, but which does nottend to break during placement or removal and which is easily removablewithout prolonged or invasive surgical cutting of subcutaneous tissue.There is also a need in the art for a device for safely removing such astabilizing device from a subcutaneous location without the need forsurgical cutting of the subcutaneous tissue.

SUMMARY OF THE INVENTION

The catheter stabilizing cuff of the present invention providesstructural reinforcement to a catheter such that the catheter does nottend to break during catheterization or removal. It is easily removablewithout prolonged or invasive surgical cutting of subcutaneous tissue.Further, it can be removed without any surgical cutting when using thedevice for removing a catheter assembly of the present invention.

The present invention includes a composite catheter stabilizing devicewhich includes a cuff and a first and second end piece. The cuff has afirst edge and a second edge, and is configured for positioning around acatheter. The device also includes a first end piece and a second endpiece. The first and second end pieces have internal surfaces whichdefine tubular openings that extend through the end pieces. The firstend and second end pieces have external surfaces which are tapered fromtheir first sides to their second sides. The first sides of the firstand second end pieces abut the first and second edges of the cuff,respectively. The second sides of the first and second end pieces areconfigured for receiving a catheter in facing engagement.

The invention also includes a catheter assembly which includes acatheter and a catheter stabilizing device. The catheter has an externalsurface and at least one lumen which extends through the catheter. Thestabilizing device includes a cuff, a first end piece and a secondpiece. The cuff has a first edge and a second edge, and is adhered tothe external surface of the catheter. The first and second end pieceshave external surfaces and internal surfaces which are configured toconform to the external surface of the catheter in facing engagement.The external surfaces of the first and second end pieces are taperedfrom the first sides of the first and second end pieces, whichrespectively abut the first and second edges of the cuff, to the secondsides of the first and second end pieces.

The invention also includes a method for making a catheter assemblyhaving a composite catheter stabilizing device. A cuff having a firstedge and a second edge is affixed to the external surface of a catheter.A first end piece having an internal surface, a first side and a secondside is positioned around the external surface of the catheter such thatthe first side abuts the first edge of the cuff. A second end piecehaving an internal surface, a first side and a second side is positionedaround the external surface of the catheter such that the first sideabuts the second edge of the cuff. The first and second end pieces aretapered from their first sides to their second sides. The first andsecond end pieces are affixed to the external surface of the cathetersuch that the second sides of the end pieces are in facing engagementwith the external surface of the catheter.

In an alternative embodiment, the method includes forming a unitarycatheter which has an external surface, a lumen extending through thecatheter, and a first and a second end piece. The first and second endpieces are tapered from the external surface of the catheter to firstsides which lie in a plane perpendicular to the longitudinal axis of thecatheter. The first sides of the first and second end pieces are facingand spaced from each other. A cuff having a first edge and a second edgeis affixed to the external surface of the catheter between the first andsecond end pieces such that the first edge of the cuff abuts the firstside of the first end piece and the second edge of the cuff abuts thefirst side of the second end piece. The end pieces and the cuff form thecomposite catheter stabilizing device.

An alternative embodiment of a composite catheter stabilizing device isincluded in the invention which includes a unitary base and a cuff. Thebase has an internal surface which defines a tubular opening thatextends through the base and that has a first end piece, a second endpiece, and an annular central portion positioned between the first andsecond end pieces. The first end piece has an external surface taperedfrom a first side toward a second side, the second end piece has anexternal surface tapered from a first side to a second side and theinternal surface is configured for positioning around a catheter. Thecuff has a first edge that abuts the first side of the first end pieceand a second edge that abuts the first side of the second end piece. Thecuff is configured for positioning around the central portion of thebase.

An alternative method is also provided for making a catheter assemblyhaving a composite catheter stabilizing device. The method includesaffixing a base to the external surface of the catheter. The base has aninternal surface which defines a tubular opening and has a first endpiece, a second end piece and a central portion. The base is affixed tothe catheter such that the internal surface of the base is in facingengagement with the external surface of the catheter. The externalsurfaces of the first and second end pieces are each tapered from afirst side to a second side. A cuff is affixed to the external surfaceof the central portion of the base such that a first edge of the cuffabuts the first side of the first end piece and a second edge of thecuff abuts the first side of the second end piece.

A device for removing a catheter assembly having a catheter stabilizingdevice including a tissue ingrowth cuff from a subcutaneous location isalso provided in the present invention. The device includes a handle anda head. The handle has a proximal end, and a distal end. The head isattached to the distal end of the handle, and has an external grippingsurface. The head is sized for insertion into a lumen of a catheterassembly having a tissue ingrowth cuff for gripping an internal surfaceof the catheter assembly within the cuff and dislodging the cuff fromsurrounding tissue.

A method for removing a catheter assembly having a catheter stabilizingdevice including a tissue ingrowth cuff which is grown into asubcutaneous location is also included in the present invention. Thecatheter assembly is removed by a device having a handle and a headhaving an external gripping surface. The method includes inserting thehead of the device into a proximal end of a lumen extending through thecatheter assembly, inserting the head further into the lumen by pushingthe handle of the device until a distal end of the head is substantiallylongitudinally aligned with a distal end of the tissue ingrowth cuff,and pulling the handle to dislodge the tissue ingrowth cuff and toremove the catheter assembly from the subcutaneous location.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description of the preferred embodiment of the invention,will be better understood when read in conjunction with the appendeddrawings. For the purpose of illustrating the invention, there are shownin the drawings embodiments which are presently preferred. It should beunderstood, however, that the invention is not limited to the precisearrangements and instrumentalities shown. In the drawings, like numeralsare used to indicate like elements throughout. In the drawings:

FIG. 1 is a plan view of a preferred embodiment of a catheter having astabilizing device affixed to the external surface of the catheteraccording to the present invention;

FIG. 2 is an enlarged plan view of the catheter stabilizing device ofFIG. 1;

FIG. 2A is cross-sectional view of the catheter stabilizing device ofFIG. 2 taken along line 2A--2A;

FIG. 2B is a cross-sectional view of the catheter stabilizing device ofFIG. 2A taken along line 2B--2B;

FIG. 2C is a cross-sectional view of the catheter stabilizing device ofFIG. 2A taken along line 2C--2C;

FIG. 3 is a plan view of a preferred method for making a catheterassembly having a composite catheter stabilizing device according to thepresent invention;

FIG. 4 is an enlarged perspective view of an alternative method formaking a catheter assembly having a composite catheter stabilizingdevice according to the present invention;

FIG. 5 is a partially broken away perspective view of a catheterassembly according to the present invention being removed from asubcutaneous location with a removal device according to the presentinvention;

FIG. 5A is an enlarged portion of the catheter assembly and removaldevice of FIG. 5 enclosed within the broken circle; and

FIG. 6 is a cross-sectional view of a catheter having an alternativeembodiment of a stabilizing device according to the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Certain terminology is used in the following description for convenienceonly and is not limiting. The words "right," "left," "lower," "upper,""downward" and "outward" designate directions in the drawings to whichreference is made. The terminology includes the words above specificallymentioned, derivatives thereof, and words of similar import.

Referring now to the drawings in detail, there is shown in FIG. 1 acatheter assembly, generally designated as 10, having a catheter 12 anda stabilizing device 14 according to the present invention. The catheter12 has an external surface 16 and at least one lumen 18 extendingtherethrough. It will be understood, based on this disclosure, that thecatheter 12 may be any catheter suitable for introducing or removingfluid from the body which requires subcutaneous securement, including,for example, a Tesio catheter, a single-lumen catheter, a shunt ordrainage tube, a parenteral nutrition catheter, an oncologic catheter, aperitoneal dialysis catheter, a dual-lumen catheter, a triple-lumencatheter and the like.

The catheter 12, and the stabilizing device 14 may be formed of the sameor different materials. Either or both of the catheter 12 and thestabilizing device 14 are preferably made of a biocompatible plastic orelastomer, more preferably from a biocompatible elastomer. Suitablebiocompatible plastics include materials such as, for example,polyethylene, homopolymers and copolymers of vinyl acetate such asethylene vinyl acetate copolymer, polyvinylchlorides, homopolymers andcopolymers of acrylates such as polymethylmethacrylate,polyethylmethacrylate, polymethacrylate, ethylene glycol dimethacrylate,ethylene dimethacrylate and hydroxymethyl methacrylate, polyurethanes,polyvinylpyrrolidone, 2-pyrrolidone, polyacrylonitrile butadiene,polycarbonates, polyamides, fluoropolymers such aspolytetrafluoroethylene and polyvinyl fluoride, polystyrenes,homopolymers and copolymers of styrene acrylonitrile, cellulose acetate,homopolymers and copolymers of acrylonitrile butadiene styrene,polymethylpentene, polysulfones, polyesters, polyimides,polyisobutylene, polymethylstyrene and other similar compounds known tothose skilled in the art. It should be understood that these possiblebiocompatible polymers are included above for exemplary purposes andshould not be construed as limiting. If a biocompatible polymericmaterial is used to form the catheter 12 and/or the stabilizing device14, it is most preferred that the polymeric material includes apolyurethane or a polyolefin polymeric material.

Suitable, preferred, biocompatible elastomers for use in forming thecatheter 12 and the stabilizing device 14 include biocompatibleelastomers such as medical grade silicone rubbers, polyvinyl chlorideelastomers, polyolefin homopolymeric and copolymeric elastomers,urethane-based elastomers, and natural rubber or other syntheticrubbers. The catheter may be formed of any of the above materials, orsimilar materials, depending upon the particular application of thecatheter 12. For the purposes of describing the preferred embodiment ofthe assembly 10 herein, the stabilizing device 14 will be described incombination with a single-lumen Tesio catheter as shown in FIG. 1,however, it should be understood, that the invention is not limited touse on Tesio catheters.

Preferably, the stabilizing device 14 is made of elastomeric materialsuch that the stabilizing device 14 is flexible, durable, and easilyconformable to the shape of the subcutaneous location in which thecatheter 12 is to be stabilized. The material used for making the device14 may be of varying degrees of hardness. It is preferred that if thecatheter 12 and the stabilizing device 14, are used for hemodialysisapplications particularly, that they be formed of a silicone elastomerwhich preferably has a hardness of at least about 80-A on a Shoredurometer scale. While it is preferred to have a higher Shore durometerhardness if a biocompatible elastomer is used, particularly forhemodialysis, it is also possible to make a device from an elastomerhaving a lower Shore durometer hardness without departing from thespirit of the invention.

It will be understood, based on this disclosure, that the catheters 12and stabilizing device 14 may also be radiopaque depending on theirintended use.

The device 14 includes a cuff 15, preferably including a material suchas Dacron® polyester and similar materials which are useful for formingtissue ingrowth cuffs in a manner which will be known to those skilledin the art based on this disclosure. Such a cuff may further beimpregnated with, for example, antibacterial substances, silver,antibiotics and the like. While a fabric tissue ingrowth cuff ispreferred, the cuff 15 may also be formed of other biocompatiblematerials, or biocompatible materials having a fabric tissue ingrowthcuff on their external surface, as long as the device 14 includes ameans for stabilizing the device 14 within a subcutaneous location.

The cuff is configured for positioning around a catheter, for example,if a fabric cuff 15 is used, the cuff 15 is cut into a generallyrectangular-shaped piece of fabric and then fitted on a proximal portionof the catheter 12 which will be positioned in a subcutaneous locationfor stabilizing the catheter 12. The location of the cuff 15 and thedevice 14 on the catheter 12 depends upon the particular application ofthe catheter. For example, for a Tesio catheter, the device 14 would bepositioned such that the cuff 15 would lie within a subcutaneous tunnelformed proximal to a vessel in the body, such as the internal jugularvein, when that vessel has been catheterized with a distal portion ofthe catheter 12. Surrounding tissue cells within the tunnel will growinto the fabric cuff 15 stabilizing the catheter in the subcutaneouslocation.

The generally rectangular portion of fabric is wrapped around thecatheter preferably only one time without any overlapping of the fabric.The fabric cuff is affixed or adhered to the external surface 16 of thecatheter 12 to form the cuff 15. The cuff may be affixed by any suitablemedical grade adhesive. Any suitable pressure or heat sensitive medicalgrade adhesive may be used such as, for example, Dow Corning SiliconeMedical Grade Adhesive. However, other biocompatible adhesives are alsoacceptable. Once the cuff 15 is positioned around the catheter 12, thecuff 15 has a first edge 17 and a second edge 19 as shown in FIGS. 2 and2A.

The first end piece 20 and the second end piece 22 of the stabilizingdevice 14 preferably have respective internal surfaces 24, 26 whichdefine respective tubular openings 28, 30 that extend through the endpieces and which are preferably configured to conform to the externalsurface of the catheter on which they are used, preferably in facingengagement. The openings 28, 30 are preferably generally cylindricallyshaped for use on catheters having a generally circular cross section.However, the cross section of the openings 28, 30 may be oval,elliptical or other similar shapes depending primarily on the shape ofthe catheter on which the device is to be used.

The first end piece 20 has an external surface 31 which is tapered froma first side 32 which abuts the first edge 17 of the cuff 15 to a secondside 34. The end piece 20 is tapered radially such that the outerdiameter of the first side 32 is larger than the outer diameter of thesecond side 34. The decrease in the diameter from the first side 32 tothe second side 34 may be constant over the end piece 20 such that apreferred frustoconically-shaped end piece 20 is formed or may bevariable such that a more curved shaped end piece 20, for example, a"football"-shape, a "bullet"-shape or similar elliptical shape, isformed.

If the end piece 20 is tapered with a constantly decreasing diameter toform a frustoconically-shaped end piece, depending upon the diameter ofthe first side 32, the angle corresponding to the slope of the taper, asmeasured between the longitudinal axis of the catheter and the externalsurface of the end piece 20 may range from about 20° to 75°, preferablyabout 25° to about 50°, and more preferably about 40° to about 50°. Theangle may be smaller or larger depending upon several factors,including, the material of construction of the catheter, the width ofthe opening 28, and the type of tissue in which the device will belocated. For example, a device having a smaller width opening 28 such as9 FR would be typically used with a catheter having a comparably smalldiameter. Smaller catheters in general, may require additionalreinforcement and will be used in smaller subcutaneous locations suchthat the angle of taper will also be smaller. An end piece 20 as used ona larger diameter catheter, for example, an 18 FR catheter, may requirea larger angle of taper.

When the catheter is formed of a material which is more likely to breakupon application of a pulling force on the catheter, i.e., a siliconematerial, may require a smaller angle of taper than necessary with moreresilient materials to provide additional structural reinforcement tothe catheter.

The second end piece 22 also has an external surface 35 which is taperedfrom a first side 36 which abuts the second edge 19 of the cuff 15 to asecond side 38 in the same manner as the first end piece 20. The secondsides 34, 38 of the end pieces 20, 22 are preferably configured toreceive the external surface 16 of the catheter 12 in facing engagementto prevent fluid from entering the device.

In the preferred design shown in FIGS. 2A to 2C, the first sides 32, 36of the first and second end pieces 20, 22 have generally annularcross-sections which lie in planes generally perpendicular to thelongitudinal axis of the catheter 12. Preferably, the first sides 32, 36have a cross-sectional diameter d₁ as shown in FIG. 2B which issubstantially the same as the cross-sectional outer diameter d₂ of thecuff 15 as shown in FIG. 2C when it is positioned around the catheter 12as shown in FIGS. 2A to 2C. The first sides 32, 36 when positionedagainst the cuff 15 should be flush with the edges 17, 19 of the cuff tosubstantially prevent tissue ingrowth into the edges 17, 19 of the cuff.

It is also preferred that the first and second end pieces 20, 22 arefrustoconically shaped to facilitate passage through the subcutaneouslocation in which the catheter 12 is to be stabilized. The taperedportion and decreased diameter of the end pieces 20, 22 helps reducefriction and drag while moving through a subcutaneous location, but thediameter of the cuff is still capable of providing a sufficiently snugfit in the subcutaneous location to allow for prevention of bleeding andfor promoting tissue ingrowth.

In addition, while it is possible to form the end pieces 20, 22 suchthat they are hollow and only in facing engagement with the externalsurface 16 of the catheter 12 at their second sides 34, 38, it ispreferred, for stronger structural integrity, that the first and secondend pieces 20, 22 are solid, as shown in FIG. 2, along their entirelength. As such, it is preferred that the internal surfaces 24, 26 beflush with the internal surface 16 of the catheter 12. By forming thedevice 14 in this manner, the risk of blood or tissue entering betweenthe device 14 and the catheter 12 is minimized.

The end pieces 20, 22 may be separately formed and heat-molded to thecatheter 12 after manufacture of the catheter 12 by any suitableheat-molding method, including injection molding, transfer molding, RFinduction and the like. Alternatively, they may be integrally formed byusing such heat-molding methods to form the catheter 12 as a unitarycatheter having the end pieces 20, 22 pre-formed on the external surface16 as shown in FIG. 4. If the end pieces 20, 22 are separately formed,they may also be affixed to the external surface 16 of the catheter 12by a medical grade adhesive, by ultrasonic welding using an ultrasonichorn in a manner which will be known to those skilled in the art or byany other suitable method of adhesion.

An alternative embodiment of a catheter assembly 10' is shown in FIG. 6.The alternative assembly 10' includes a catheter 12 and a compositecatheter stabilizing device 14' which includes a unitary base 62. Thecatheter may be any suitable catheter 12 as described above with respectto assembly 10. The base 62 has an internal surface 64 which defines atubular opening 66 that extends through the device 14'. The internalsurface 64 is configured for positioning around a catheter 12. The base62 may be formed of the same materials used to form the first and secondend pieces 20, 22 of assembly 10.

The base 62 is integrally formed of a first end piece 20', a second endpiece 22' and an annular central portion 68 positioned between the ends20', 22'. The end pieces 20', 22' are identical to the end pieces 20, 22described above, with the exception that they are interconnected by thecentral annular portion 68. The unitary base 62 may be separatelyformed, or formed as a part of a unitary catheter assembly in the mannershown in FIG. 4, and as described herein, with respect to the catheterassembly 10.

If formed independently of the catheter 12, the base 62 may be affixedto the external surface of the catheter 12 by any suitable heat moldingmethod or by use of adhesive, ultrasonic welding or any other suitablemethod of adhesion. By connecting the end pieces 20', 22' with thecentral portion 68 to form a unitary base 62, the device 14' hasenhanced structural integrity which may provide further reinforcementfor the catheter 12 within the assembly when pulling the proximalportion of the catheter through a subcutaneous location.

A cuff 15' has a first edge abutting the first side of the first endpiece 20' and a second edge abutting the first side of the second endpiece 22' in a manner similar to that shown with respect to assembly 10.The cuff 15' is configured for positioning around the exterior surface70 of the annular central portion 68 as shown in FIG. 6. The cuff may beaffixed to the central portion 68 by any suitable method, for example,in the same manner as the cuff 15 is affixed to the external surface ofthe catheter 12 in the composite device 14 of assembly 10 describedabove.

Methods for making the catheter assembly 10 having a composite catheterstabilizing device are also included in the present invention. In oneembodiment as shown in FIG. 3, a cuff, such as the cuff 15 describedabove, is affixed to the external surface 16 of a catheter, such as thecatheter 12 described above. Preferably, a tissue ingrowth fabric cuffhaving an adhesive layer on one surface of the cuff 15 is wrapped aroundthe external surface of the catheter 12 such that the adhesive affixesthe cuff 15 to the catheter in the manner shown in FIG. 3.

A first end piece 20 having an internal surface 24 which defines atubular opening 28 as shown in FIG. 2A is positioned around the externalsurface 16 of the catheter such that the first side 32 of the end piece20 abuts the first edge 17 of the cuff 15. The second end piece 22 hasan internal surface 26 which defines a tubular opening 30 as shown inFIG. 2A. The end piece 22 is positioned around the external surface 16of the catheter 12 such that the first side 36 abuts the second edge 19of the cuff 15.

The first and second end pieces 20, 22 are affixed to the externalsurface of the catheter such that the internal surfaces 24, 26 of theend pieces 20, 22 are preferably in facing engagement with the externalsurface 16 of the catheter 12. Preferably, the first and second endpieces are affixed to the catheter 12 by any suitable method ofheat-molding the first and second end pieces onto the catheter in amanner which will be understood by those skilled in the art. Preferably,the first and second end pieces 20, 22 are affixed to the catheter by asuitable method of transfer molding. Alternatively, the first and secondend pieces may be affixed to the external surface of the catheter 12 byuse of an adhesive or by ultrasonically welding the pieces 20, 22 to theexternal surface 16.

In an alternative method for making a catheter assembly having acomposite catheter stabilizing device, a unitary catheter 12 is formedby preferably heat molding a biocompatible polymer such as thosedescribed above. The mold should be shaped to form a unitary catheter 12having a first end piece and a second end piece in a single unit asshown in FIG. 4. Any heat-moldable process may be used to form theunitary catheter 12. The end pieces may be formed in the same manner,and will be referred to for the purposes of describing the method, assimilar to the first and second end pieces 20, 22 described above. Thefirst end piece 20 is radially tapered from an external surface of thecatheter 12 toward a first side 32, which preferably lies in a planeperpendicular to the longitudinal axis of the catheter 12 as shown inFIGS. 2 and 4. The second end piece 22 is radially tapered from theexternal surface of the catheter toward a first side 36 lying in a planeperpendicular to the longitudinal axis of the catheter. The first sideof the first portion 20 and the first side of the second portion 22 ofthe unitary molded catheter should be facing each other, but spacedapart as shown in FIG. 4.

A cuff 15, such as that described above having a first edge 17 and asecond edge 19 is affixed to the external surface 16 of the catheter 12'by a suitable adhesive between the first and second end pieces 20, 22such that the first edge 17 of the cuff 15 abuts the first side 32 ofthe first end piece 20 and the second edge 19 of the cuff 15 abuts thefirst side 36 of the second end piece 22.

The method for making the composite assembly 10', shown in FIG. 6, maybe described with reference to FIGS. 3, 4 and 6. A unitary base 62, asshown in FIG. 6 and described above, is affixed to the external surfaceof the catheter 12 such that the internal surface 64 of the base 62 isin facing engagement with the external surface of the catheter. The base62 may be affixed to the catheter by sliding the base 62 along thecatheter and affixing the base 62 to the external surface with anadhesive, by any suitable heat-molding method, or by ultrasonic welding,in a manner similar to the method as shown in FIG. 3 for the assembly10.

Alternatively, the base as shown in FIG. 6 may be integrally molded witha catheter 12 to form a unitary assembly 10' in a manner similar to themethod of forming the unitary assembly 10 including the device 14 asshown in FIG. 4.

The cuff 15' is then affixed to the external surface 70 of the annularcentral portion 68 of the base 62 by any suitable method of adhesionsuch that the edges of the cuff 15' abut the first sides of the firstand second end pieces 20', 22'. The cuff 15' may be affixed to thecentral portion 68 by any suitable method such as those described abovewith respect to affixing the cuff 15 to the external surface of thecatheter 12 when making assembly 10.

By forming a composite stabilizing device 14 or 14' such as thosedescribed above, the removal of the catheter 12 from the subcutaneouslocation is greatly simplified and improved. Because of the design ofthe device 14, 14' as shown in FIGS. 1, 2, 2A, 4 and 6, wherein theedges 17, 19 of the cuff abut the end pieces 20, 22, growth ofsubcutaneous tissue into the first and second edges 17, 19 of the cuff,as occurs with ordinary stabilizing cuffs, is substantially preventedand tissue grows only in a direction generally perpendicular to thelongitudinal axis of the catheter assembly. The positioning of the endpieces 20, 22 substantially prevents tissue from growing into the edges17, 19 of the cuff. Thus, to remove the catheter, the physician needonly cut around the external circumference of the cuff to extricate thecuff from the subcutaneous tissue.

The tapered design of the end pieces allows for a smoother passage ofthe cuff through a subcutaneous area, while still providing asufficiently snug fit for tissue ingrowth. Further, the stabilizingdevices 14, 14' provide additional reinforcement to the catheter at thepoint where the most stress is applied in pulling the catheter through asubcutaneous area to help minimize the risk of catheter breakage.

The catheter assemblies 10, 10' can be removed without unnecessarycutting by using a scalpel or a cutting tool shaped to fit around thedevices 14, 14'. Such a tool can be configured to have a hollowcylindrical cutting surface which has an inner diameter approximatingthe outer diameter d₂ of the fabric cuff 15. Upon insertion of thecutting tool around the device 14, the tool can be carefully forced overthe device 14 such that the tissue around the cuff 15 is easily severedfrom the fabric. Once the tissue is severed, the catheter assembly 10,including the device 14 can be easily slid out of the subcutaneous area.The physician can then close the area quickly.

Preferably, as shown in FIGS. 5 and 5A, the catheter assembly 10 havinga catheter stabilizing device 14 according to the present invention isremoved from a subcutaneous location 40 without any surgical cutting.The assembly 10 may be removed by inserting a device 42 having a havinga handle 44 and a head 46. The handle 44 has a distal end 48 which isattached to the head 46 for inserting into the lumen 18 of the catheterassembly 10 and a proximal end 50 which is held by the physician forinserting the device 42. Preferably the handle 44 extends in thelongitudinal direction from the distal end 48 to the proximal end 50,and has a length sufficient to enable the head 46 to be positionedwithin the catheter stabilizing device 14, while the proximal end 50 ofthe handle extends outwardly from the proximal end 60 of the catheterassembly 10 a sufficient distance to enable the physician to manipulatethe handle 44.

The head 46 and handle 44 may be formed as a single unit, or formedseparately and fit together by soldering, snap-fit, mating threads orother similar attachment methods. The handle 44 and the head 46 may bemade of any relatively rigid material, for example, steel or othermetals, or a hard durometer plastic or elastomeric material. The head ispreferably cylindrically-shaped if the internal surface of the catheteris generally circular in cross section, but the shape of the head 46 maybe varied in order to conform to the internal surface 54 of the catheterassembly. While it is preferred that the shape of the head 46 conform tothe shape of the internal surface 54 of the catheter assembly 10, it isnot necessary as long as the head is shaped to fit within the lumen 18,and to sufficiently grip the surface 54, to dislodge the stabilizingdevice 14 from the surrounding tissue and pull the assembly from thesubcutaneous location.

The head has an external gripping surface 52, which is preferablyuneven, so that the head 46 can grip the internal surface 54 of thecatheter assembly 10. The surface 52 may have raised projections such assmall spikes, ribs and the like. Preferably, the surface 52 has threads56 as shown in FIGS. 5 and SA.

The diameter d₃ of the head 46, as measured in a direction perpendicularto the longitudinal axis of the device 42, when the head is generallycircular in cross-section, is preferably larger than the diameter d₄ ofthe handle 44. The head 46 is sized such that upon insertion of the head46 into the lumen 18 of the catheter assembly 10, the surface 52 gripsthe internal surface 54 of the assembly 10.

If threads 56 are provided, the head 46 may be rotated, by rotating thehandle 44, such that the head is screwed into the lumen 18 for a snugfit between the gripping surface 52 and the internal surface 54 of theassembly 10. By gripping the internal surface 54, pulling force exertedon the proximal end 50 of the handle 44 will dislodge the cuff 15 of thestabilizing device 14 from the portion of the subcutaneous location 40into which it has ingrown without surgical cutting. After dislodging,additional pulling force on the proximal end 50 of the handle 44 willremove the assembly 10 from the subcutaneous location 40.

For more easy insertion of the head 46 into the lumen 18, the head 46preferably also has a tapered distal end 58 as shown in FIGS. 5 and 5A.The distal end 58 may be pointed or rounded, preferably, the distal end58 of the head 46 is conical with a smoothly rounded tip.

The method for removing a catheter assembly having a catheterstabilizing device which includes a tissue ingrowth cuff, such as anassembly 10 as described above, ingrown into a subcutaneous location 40,preferably uses a device having a handle and a head having an externalgripping surface, preferably the device 42 described above. The methodincludes inserting the head 46 into the proximal end 60 of the catheterin the lumen 18 by pushing the handle 44 of the device longitudinallyinto the lumen as shown in FIG. 5. The head is then further insertedinto the lumen 18 by pushing the handle 44 until a distal end of thehead 58 is substantially aligned with the distal end, i.e. the secondside 34 of the first end piece 20 of the stabilizing device 14. Theproximal end 50 of the handle 44 is then pulled outwardly in thelongitudinal direction as shown in FIG. 5 to dislodge the tissueingrowth cuff 15 from the subcutaneous location 40. Continued pullingwill remove the assembly 10 from the location 40 without surgicalcutting.

If threads 56 are provided to the surface 52 of the head 46 of theremoval device 42, then, when the head 46 is being inserted, theproximal end 50 of the handle 46 should be rotated as shown in FIG. 5such that the head is screwed into the lumen 18 for a more snug fitbetween the head 46 and the internal surface 54 of the catheter assembly10.

This removal of the present assembly as described above is a significantimprovement over prior art removal procedures in which the physician hadto cut around the circumference and all edges of an ordinary fabric cuffsuch that the physician was, in effect, digging the cuff out of thetissue. Such a procedure causes increased bleeding and risk ofinfection. Further, due to the design of the end pieces 20, 22 of thedevice 14, the assembly slides out of the subcutaneous area much moreeasily minimizing the possibility of breakage or snapping of thecatheter in the subcutaneous area. In addition, when the removal device42 is used, no surgical cutting is required and the catheter assembly 10is easily removed from the inside of the catheter with minimal risk ofbleeding and infection to the patient.

The invention will now be described in accordance with the followingnon-limiting examples:

EXAMPLE I

Two tapered frustoconically-shaped end pieces formed of silicone andhaving 24 FR cylindrical openings extending through the end pieces arepositioned on either side of a Dacron® cuff affixed by an adhesive layerto the external surface of a single-lumen catheter of a Tesio catheterassembly. The angle of taper of the frustoconically-shaped end pieces is45°. The cuff is precut to a rectangular shape 5 mm×25 mm in dimensionand then affixed to the catheter such that the cuff fits around thecatheter one time without overlapping. The end pieces are positionedsuch that the larger diameter sides abut the edges of the cuff. The endpieces are then subjected to heat by liquid vulcanization injectionmolding such that the internal surfaces of the end pieces are in fullfacing engagement and molded onto the external surface of the catheter.

EXAMPLE II

A mold is prepared having the shape of a 10 FR single lumen catheter ofa Tesio catheter assembly having first and second end pieces positionedon a proximal portion of the catheter. The second side of the first endpiece is 17 cm from the proximal end of the catheter and the second sideof the second end piece is 22 mm from the distal end of the catheter.The end pieces are radially tapered at a constant rate of increasingradius from the external surface of the catheter toward first sideswhich lie in a plane perpendicular to the longitudinal axis of thecatheter such that frustoconically shaped end pieces are formed and theangle of taper is 20°. The first sides have annular cross-sections andan outer diameter of 6 mm. The first sides are spaced longitudinally 3.5mm from each other. The mold is filled with silicone and subjected toheat by injection molding to form a unitary catheter. The catheter isremoved from the mold.

A Dacron® cuff as described in Example I and measuring 3.5 mm by 22 mmis affixed to the external surface of the catheter in the space betweenthe frustoconically-shaped end pieces such that the edges of the cuffabut the first sides of the end pieces.

EXAMPLE III

A unitary base of a stabilizing device having two end pieces andmeasuring 1.7 cm longitudinally from the second side of the first endpiece to the second side of the second end piece is formed by injectionmolding. The end pieces of the unitary base each have an angle of taperof 20°. The central portion of the base is 3.5 mm as measuredlongitudinally between the two end pieces and has a thickness measuredfrom the interior surface of the central portion to the exterior surfaceof the central portion of about 0.5 mm. The unitary base has a 10 FRcylindrically-shaped opening extending through the base. The base isslid over a 10 FR single lumen catheter from a Tesio catheter assemblyuntil the base is 17 cm from the proximal end and 22 cm from the distalend of the catheter. The unitary base is then heat molded to theexterior surface of the catheter by liquid vulcanization injectionmolding.

It will be appreciated by those skilled in the art that changes could bemade to the embodiments described above without departing from the broadinventive concept thereof. It is understood, therefore, that thisinvention is not limited to the particular embodiments disclosed, but itis intended to cover modifications within the spirit and scope of thepresent invention as defined by the appended claims.

I claim:
 1. A composite catheter stabilizing device useful for anchoringcatheter to subcutaneous tissue, comprising:(a) a cuff having a firstedge and a second edge, the cuff being configured for positioning arounda catheter; (b) a first end piece having an internal surface defining atubular opening extending therethrough and an external surface taperedfrom a first side abutting the first edge of the cuff toward a secondside, the first side having a generally annular cross section and adiameter which is substantially the same as an outer diameter of thecuff when the cuff is positioned around a catheter; and (c) a second endpiece having an internal surface defining a tubular opening extendingtherethrough and an external surface tapered from a first side abuttingthe second edge of the cuff toward a second side, the first side havinga generally annular-cross section and a diameter which is substantiallythe same as an outer diameter of the cuff when the cuff is positionedaround a catheter, wherein the second sides of the first and second endpieces are configured for receiving a catheter in facing engagement, andthe first and second end pieces are configured to conform to an externalsurface of a catheter in facing engagement for facilitating smoothmovement of a catheter through subcutaneous tissue, wherein an internaldiameter of the composite catheter stabilizing device is dimensioned tobe substantially the same as an external diameter of a catheter forenabling the composite catheter stabilizing device to be affixed to andto conform to an external surface of the catheter and to be capable ofmoving through subcutaneous tissue without detaching from a catheter inorder to subcutaneously anchor a catheter in subcutaneous tissue.
 2. Thedevice according to claim 1, wherein the first and second end pieces arefrustoconical and the openings in the first and second end pieces arecylindrically shaped.
 3. The device according to claim 2, wherein theinternal surfaces of the first and second end pieces are configured forbeing flush with the catheter when the catheter is within thecylindrically shaped openings.
 4. The device according to claim 1,wherein the cuff comprises a biocompatible fabric capable of tissueingrowth.
 5. The device according to claim 1, wherein the first andsecond end pieces comprise a silicone material.
 6. A composite catheterstabilizing device useful for anchoring a catheter to subcutaneoustissue, comprising:(a) a unitary base having an internal surfacedefining a tubular opening extending therethrough and having a first endpiece, a second end piece, and an annular central portion positionedbetween the first and second end pieces, wherein the first end piece hasan external surface tapered from a first side having an outer diametertoward a second side, the second end piece has an external surfacetapered from a first side having an outer diameter to a second side andthe internal surface configured for conforming to an external surface ofa catheter in facing engagement, wherein an internal diameter of theunitary base device is dimensioned to be substantially the same as anexternal diameter of a catheter for enabling the unitary base to beaffixed to and conform to an external surface of the catheter; (b) acuff having a first edge abutting the first side of the first end pieceand a second edge abutting the first side of the second end piece, thecuff having an outer diameter which is substantially the same as theouter diameter of the first side of the first end piece and as the outerdiameter of the first side of the second end piece and being configuredfor positioning around the central portion of the base, wherein the baseis configured for facilitating smooth movement of a catheter throughsubcutaneous tissue, and wherein the composite catheter stabilizingdevice is capable of moving through subcutaneous tissue withoutdetaching from a catheter in order to subcutaneously anchor a catheterin subcutaneous tissue.